Gypsy, to my knowledge there have been a few easy pilots who've left easyland for Go - in the early days.
The recent flow back (was it three captains ? ) was more to do with the joining 'bung' than any other issue. Putting some flesh on that, to my knowledge one was a few years away from retirement and saw the golden hello as a nice little top-up for his pension fund, the next was a proverbial thorn in the side of Go management and whom I'm sure they were glad to see the back of, the last was a trainer (who'd previously worked for easy) but who found it hard to say no to the joining money (wasn't it £30,000 for a trainer ?) ; and if memory serves me right, all three live closer to LTN than to STN.
Of course, the joining bung must have done wonders for the moral of those who'd joined easy just a few weeks prior to its inception, and ultimately easy did all the captains at Go a great favour as it forced their company into rather dramatic pay hike.
I can say that during that time loads of Go pilots went to the easy interviews - but very few subsequently left (see above).
Also, it would be true to say that ADC knows a lot more about the why's and wherefores of it all than can be openly discussed here on PPRuNe.
The reality of it is that it (IMHO) was always seen as follows:
RyanAir work their crew the hardest (Irish AOC / rules) but that they take home the most money (their basic is actually p!ss poor and the money is made up via productivity deals).
Easy pay well but muck their crews lifestyle about something rotten (lots of roster changes - due to shortage of crew ? ).
Go didn't pay so well but had a more stable lifestyle and (originally) did less work.
Well that's at least how it used to be perceived. However nowadays one might say that:
RyanAir still work their crews to death, but they still take home the most dosh.
easy and Go are now very similar (easy have put effort into fixing the rostering), Go have upped the money, and both now work lots of hours (i.e. Go pilots are hitting 900 hours all the time).
Actually I'm pretty sure that if you took the average net pay of all these airlines and then divided that by the hours flown that the hourly rates of pay would all be pretty close.
Which then means that it's a lifestyle choice, e.g. based on where you live w.r.t. your base, how much the basic pay is (coz it effects your pension), etc....